Rurumo
Well-Known Member
Hi everyone!
I've been thinking a lot lately about mixing up a batch of Cootz mix for a new grow now that the weather is getting nice and I could get it cooking outside, but after researching heavy metals in mineral salts and traditional organic inputs over the winter, I started wondering about rock dusts. We all know rock phosphate is frequently problematic, and is the primary source of long term cadmium accumulation in agricultural soils worldwide. Likewise, it's becoming a bit more common knowledge that kelp meal (any type of seaweed really) is a significant source of arsenic. These two materials alone are responsible for countless cannabis samples failing their heavy metal testing.
But what about rock dusts? I've used Cootz type mixes off and on for years and have applied rock dusts to great effect in my vegetable garden....but I've never thought to consider their heavy metal content until now. So I went to my trusty site for registered fertilizers-https://apps1.cdfa.ca.gov/fertilizerproducts/-hoping it would be as easy as just typing in "basalt" or "rock dust" and luckily, it was! It won't let me link the exact products to you, but if you search for basalt, rock dust, and azomite, you can find many examples of the most commonly used rock dusts and the results are a bit disturbing. They are variously high in cadmium, arsenic, and lead as well as other heavy metals that you might not really be concerned about, like nickel. Some are high in just a few, others, in all of them. If you use rock dusts, I'd encourage you to go and search the site for yourself. Dolomite also appears to have especially high levels of arsenic, though some samples are no slouches when it comes to other metals.
I've always preferred organic growing, especially outdoors, and I'll continue to do so, but this has really opened up my eyes to questioning the inputs we use. Suffice it to say, I will no longer be using rock dusts of any kind. I hope people wake up to this "hidden" danger of organic growing. Not long ago a ton of organic baby foods turned out to be extremely high in lead-now I'm not all that surprised. Elliot Coleman has been preaching the benefits of rock dusts and remineralizing the soil for decades, and the 2 organic farms I know of make use of it.
What I would like is for organic growers to be as concerned about heavy metals as they are about pesticides or "chemical" fertilizers. Rather than set "low" allowable amounts for these heavy metals, I'd like for regulators to be pressured into setting NO ALLOWABLE AMOUNT-because it's possible, and it's not cost prohibitive to seek out fertilizers and various agricultural inputs that have no detectable level of these metals.
I'm going to take a few days and rework some recipes with materials that are free of heavy metals. Bone meal is frequently tainted, while fish bone meal usually is not, for example. There are excellent replacements for most of these problematic materials. Keep in mind, liquid organic nutrients have many of the same issues-Earth Juice and Nectar For the Gods have many products that contain arsenic and cadmium, while Age Old Organics and Bio Bizz, are mostly clean-Bio Bizz perhaps because as a European product, maybe it's subjected to higher standards?
I'm sorry if I pooped in anyone's cornflakes! BUT, nothing will ever change unless more people know about this and DEMAND change with their wallets! Good luck to you my friends.
I've been thinking a lot lately about mixing up a batch of Cootz mix for a new grow now that the weather is getting nice and I could get it cooking outside, but after researching heavy metals in mineral salts and traditional organic inputs over the winter, I started wondering about rock dusts. We all know rock phosphate is frequently problematic, and is the primary source of long term cadmium accumulation in agricultural soils worldwide. Likewise, it's becoming a bit more common knowledge that kelp meal (any type of seaweed really) is a significant source of arsenic. These two materials alone are responsible for countless cannabis samples failing their heavy metal testing.
But what about rock dusts? I've used Cootz type mixes off and on for years and have applied rock dusts to great effect in my vegetable garden....but I've never thought to consider their heavy metal content until now. So I went to my trusty site for registered fertilizers-https://apps1.cdfa.ca.gov/fertilizerproducts/-hoping it would be as easy as just typing in "basalt" or "rock dust" and luckily, it was! It won't let me link the exact products to you, but if you search for basalt, rock dust, and azomite, you can find many examples of the most commonly used rock dusts and the results are a bit disturbing. They are variously high in cadmium, arsenic, and lead as well as other heavy metals that you might not really be concerned about, like nickel. Some are high in just a few, others, in all of them. If you use rock dusts, I'd encourage you to go and search the site for yourself. Dolomite also appears to have especially high levels of arsenic, though some samples are no slouches when it comes to other metals.
I've always preferred organic growing, especially outdoors, and I'll continue to do so, but this has really opened up my eyes to questioning the inputs we use. Suffice it to say, I will no longer be using rock dusts of any kind. I hope people wake up to this "hidden" danger of organic growing. Not long ago a ton of organic baby foods turned out to be extremely high in lead-now I'm not all that surprised. Elliot Coleman has been preaching the benefits of rock dusts and remineralizing the soil for decades, and the 2 organic farms I know of make use of it.
What I would like is for organic growers to be as concerned about heavy metals as they are about pesticides or "chemical" fertilizers. Rather than set "low" allowable amounts for these heavy metals, I'd like for regulators to be pressured into setting NO ALLOWABLE AMOUNT-because it's possible, and it's not cost prohibitive to seek out fertilizers and various agricultural inputs that have no detectable level of these metals.
I'm going to take a few days and rework some recipes with materials that are free of heavy metals. Bone meal is frequently tainted, while fish bone meal usually is not, for example. There are excellent replacements for most of these problematic materials. Keep in mind, liquid organic nutrients have many of the same issues-Earth Juice and Nectar For the Gods have many products that contain arsenic and cadmium, while Age Old Organics and Bio Bizz, are mostly clean-Bio Bizz perhaps because as a European product, maybe it's subjected to higher standards?
I'm sorry if I pooped in anyone's cornflakes! BUT, nothing will ever change unless more people know about this and DEMAND change with their wallets! Good luck to you my friends.